1000 Base-T, ±15kV ESD Protection LAN Switches

Transcription

1 ; Rev 0; 8/ Base-T, ±15kV ESD Protection LAN Switches General Description The meet the needs of high-speed differential switching. The devices handle the needs of Gigabit Ethernet (10/100/1000) Base-T switching as well as LVDS and LVPECL switching. The MAX4890E/ MAX4892E provide enhanced ESD protection up to ±15kV, and excellent high-frequency response, making the devices especially useful for interfaces that must go to an outside connection. Both devices provide extremely low capacitance (C ON ), as well as low resistance (R ON ), for low-insertion loss and very wide bandwidth. In addition to the four pairs of DPDT switches, the MAX4892E provides LED switching for laptop computer/docking station use. The are pin-for-pin equivalents to the MAX4890/MAX4892 and can replace these devices for those applications requiring the enhanced ESD protection. Both devices are available in spacesaving TQFN packages and operate over the standard -40 C to +85 C temperature range. Applications Notebooks and Docking Stations Servers and Routers with Ethernet Interfaces Board-Level Redundancy Protection SONET/SDH Signal Routing T3/E3 Redundancy Protection LVDS and LVPECL Switching TOP VIEW + A0 V+ LED2 2LED1 2LED2 0B1 Pin Configurations 1B1 0B2 1B Features ±15kV ESD Protected Per MIL-STD-883, Method 3015 Single +3.0V to +3.6V Power-Supply Voltage Low On-Resistance (R ON ): 4Ω (typ), 6.5Ω (max) Ultra-Low On-Capacitance (C ON ): 8pF (typ) -23dB Return Loss (100MHz) -3dB Bandwidth: 650MHz Optimized Pin Out for Easy Transformer and PHY Interface Built-In LED Switches for Switching Indicators to Docking Station (MAX4892E) Low 450µA (max) Quiescent Current Bidirectional 8 to 16 Multiplexer/Demultiplexer Standard Pin Out, Matching the MAX4890 and MAX4892 Space-Saving Lead-Free Packages 32-Pin, 5mm x 5mm, TQFN Package 36-Pin, 6mm x 6mm, TQFN Package PART Ordering Information PIN- PACKAGE LED SWITCHES PKG CODE MAX4890EETJ+ 32 TQFN-EP* T MAX4892EETX+ 36 TQFN-EP* 3 T Denotes lead-free package. Note: All devices are specified over the -40 C to +85 C operating temperature range. *EP = Exposed pad. Eye Diagram A1 1 A2 2 A3 3 LED0 4 0LED1 5 0LED2 6 A4 7 A5 8 A6 9 *EP MAX4892E 2B1 3B1 2B2 3B2 4B1 5B1 4B2 5B2 CH2: 4B2, 100mV/div A7 GND LED1 1LED1 1LED2 7B2 6B2 TQFN *EXPOSED PAD CONNECTED TO GND. Pin Configurations continued at end of data sheet. 7B1 6B1 CH1: 5B2, 100mV/div f = 125MHz Typical Operating Circuit and Functional Diagrams appear at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at , or visit Maxim s website at

2 ABSOLUTE MAXIMUM RATINGS V+ -0.3V to +4V All Other Pins V to (V V) Continuous Current (A_ to _B_)...±120mA Continuous Current (LED_ to _LED_). ±40mA Peak Current (A_ to _B_) (pulsed at 1ms, 10% duty cycle). ±240mA Current into Any Other Pin...±20mA Continuous Power Dissipation (T A = +70 C) 32-Pin TQFN (derate 34.5mW/ C above +70 C) W 36-Pin TQFN (derate 35.7mW/ C above +70 C) W ESD Protection, Human Body Model...±15kV Operating Temperature Range. -40 C to +85 C Junction Temperature C Storage Temperature Range C to +150 C Lead Temperature (soldering, 10s) C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V+ = +3V to +3.6V, T A = T J = T MIN to T MAX, unless otherwise noted. Typical values are at V+ = 3.3V, T A = +25 C.) (Note 1) ANALOG SWITCH PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS On-Resistance R ON I A_ = -40mA, V+ = 3V, T A = +25 C V A_ = 0, 1.5V, 3V T MIN to T MAX 6.5 Ω On-Resistance LED Switches R ONLED V + = 3V, I _L E D _ = - 40m A, V LE D _ = 0, 1.5V, 3V (MAX4892E) 40 Ω On-Resistance Match Between Channels V+ = 3V, T A = +25 C I A_ = -40mA, R ON V A_ = 0, 1.5V, 3V (Note 2) T MIN to T MAX 2 On-Resistance Flatness R FLAT(ON) V+ = 3V, I A_ = -40mA, V A_ = 1.5V, 3V 0.01 Ω Off-Leakage Current I LA_(OFF) V+ = 3.6V, V A_ = 0.3V, 3.3V; V _B1 or V _B2 = 3.3V, 0.3V On-Leakage Current I LA_(ON) V+ = 3.6V, V A_ = 0.3V, 3.3V; V _B1 or V _B2 = 0.3V, 3.3V or floating ESD PROTECTION ESD Protection SWITCH AC PERFORMANCE Human Body Model (spec MIL-STD-883, Method 3015) Insertion Loss I LOS R S = R L = 50Ω, unbalanced, f = 1MHz, (Note 2) Ω µa ±15 kv 0.6 db Return Loss R LOS f = 100MHz -23 db 2

3 1000 Base-T ±15kV ESD Protection LAN Switch ELECTRICAL CHARACTERISTICS (continued) (V+ = +3V to +3.6V, T A = T J = T MIN to T MAX, unless otherwise noted. Typical values are at V+ = 3.3V, T A = +25 C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V Any switch to any CT1 f = 25MHz -50 switch; R Crosstalk S = R L = db 50Ω, unbalanced, V CT2 f = 125MHz -26 Figure 1 SWITCH AC CHARACTERISTIC -3dB Bandwidth BW R S = R L = 50Ω, unbalanced 650 MHz Off-Capacitance C OFF f = 1MHz, _B_, A_ 3.5 pf On-Capacitance C ON f = 1MHz, _B_, A_ 6.5 pf Turn-On Time t ON V A_ = 1V, R L, 100Ω, Figure 2 50 ns Turn-Off Time t OFF V A_ = 1V, R L, 100Ω, Figure 2 50 ns Propagation Delay t PLH, t PHL R S = R L = 50Ω, unbalanced, Figure ns Output Skew Between Ports t SK(o) Skew between any two ports, Figure ns SWITCH LOGIC Input-Voltage Low V IL V+ = 3.0V 0.8 Input-Voltage High V IH V+ = 3.6V 2.0 Input-Logic Hysteresis V HYST V+ = 3.3V 100 mv Input Leakage Current I V+ = 3.6V, V = 0 or V µa Operating Supply-Voltage Range V V Quiescent Supply Current I+ V+ = 3.6V, V = 0 or V µa V Note 1: Specifications at -40 C are guaranteed by design. Note 2: Guaranteed by design. 3

4 (V+ = 3.3V, T A = +25 C, unless otherwise noted.) RON (Ω) T A = +85 C ON-RESISTANCE vs. V A_ T A = +25 C VA_ (V) T A = -40 C MAX4890E toc01 RONLED (Ω) LED_ON-RESISTANCE vs. V LED_ T A = +85 C T A = -40 C T A = +25 C V LED_ (V) Typical Operating Characteristics MAX4890E toc02 LEAKAGE CURRENT (pa) LEAKAGE CURRENT vs. TEMPERATURE IL A_ (OFF) IL A_ (ON) TEMPERATURE ( C) MAX4890E toc03 QUIESCENT SUPPLY CURRENT vs. TEMPERATURE SINGLE-ENDED INSERTION LOSS vs. FREQUENCY QUIESCENT SUPPLY CURRENT (µa) V+ = 3.6V MAX4890E toc04 INSERTION LOSS (db) MAX4890E toc TEMPERATURE ( C) FREQUENCY (MHz) 4

5 1000 Base-T ±15kV ESD Protection LAN Switch Pin Description PIN MAX4892E MAX4890E NAME FUNCTION 1 32 A1 Differential PHY Interface Pair. Connect to the Ethernet PHY. 2 1 A2 Differential PHY Interface Pair. Connect to the Ethernet PHY. 3 2 A3 Differential PHY Interface Pair. Connect to the Ethernet PHY. 4 LED0 LED0 Input 5 0LED1 0LED1 Output. Drive low ( = 0) to connect LED0 to 0LED1. 6 0LED2 0LED2 Output. Drive high ( = 1) to connect LED0 to 0LED A4 Differential PHY Interface Pair. Connect to the Ethernet PHY. 8 8 A5 Differential PHY Interface Pair. Connect to the Ethernet PHY. 9 9 A6 Differential PHY Interface Pair. Connect to the Ethernet PHY A7 Differential PHY Interface Pair. Connect to the Ethernet PHY GND Ground 12 LED1 LED1 Input 13 1LED1 1LED1 Output. Drive low ( = 0) to connect LED1 to 1LED LED2 1LED2 Output. Drive high ( = 1) to connect LED1 to 1LED B2 B2 Differential Pair B2 B2 Differential Pair B1 B1 Differential Pair B1 B1 Differential Pair B2 B2 Differential Pair B2 B2 Differential Pair B1 B1 Differential Pair B1 B1 Differential Pair B2 B2 Differential Pair B2 B2 Differential Pair B1 B1 Differential Pair B1 B1 Differential Pair Select Input. selects switch connection. See the Truth Table (Table1) B2 B2 Differential Pair B2 B2 Differential Pair B1 B1 Differential Pair B1 B1 Differential Pair 32 2LED2 2LED2 Output. Drive high ( = 1) to connect LED2 to 2LED LED1 2LED1 Output. Drive low ( = 0) to connect LED2 to 2LED1. 34 LED2 LED2 Input V+ Positive-Supply Voltage Input. Bypass to GND with a 0.1µF ceramic capacitor A0 Differential PHY Interface Pair. Connect to the Ethernet PHY. 3-6, 12 N.C. No Connection. Not internally connected. EP Exposed Pad. Connect exposed pad to GND or leave it unconnected. 5

6 SINGLE-ENDED BANDWIDTH NETWORK 50Ω TRACE ANALYZER SINGLE-ENDED CROSSTALK NETWORK 50Ω TRACE ANALYZER NETWORK ANALYZER 50Ω TRACE SINGLE-ENDED OFF-ISOLATION NETWORK 50Ω TRACE ANALYZER R Ω A0 36 A2 2 A3 3 MAX4892E A TQFN 0B Ω TRACE NETWORK ANALYZER 2B1 26 3B1 25 4B1 22 R Ω R Ω 50Ω TRACE NETWORK ANALYZER Figure 1. Single-Ended Bandwidth, Crosstalk, and Off-Isolation Detailed Description The are high-speed analog switches targeted for 1000 Base-T applications. In a typical application, the switch the signals from two separate interface transformers and connect the signals to a single 1000 Base-T Ethernet PHY (see the Typical Operating Circuit). This configuration simplifies docking station design by avoiding signal reflections associated with unterminated transmission lines in a T configuration. The are protected against ±15kV electrostatic discharge (ESD) shocks. The MAX4892E also includes LED switches that allow the LED output signals to be routed to a docking station along with the Ethernet signals. See the Functional Diagrams. With their low resistance and capacitance, as well as high ESD protection, the can be used to switch most low-voltage differential signals, such as LVDS, SEREDES, and LVPECL, as long as the signals do not exceed maximum ratings of the devices. The switches provide an extremely low capacitance and on-resistance to meet Ethernet insertion and return-loss specifications. The MAX4892E features three built-in LED switches. The incorporate a unique architecture design utilizing only n-channel switches within the main Ethernet switch, reducing I/O capacitance and channel resistance. An internal two-stage charge pump with a nominal output of 7.5V provides the high voltage needed to drive the gates of the n-channel switches while maintaining a consistently low R ON throughout the input signal range. An internal bandgap reference set to 1.23V and an internal oscillator running at 2.5MHz provide proper charge-pump operation. Unlike other charge-pump circuits, the include internal flyback capacitors, reducing design time, board space, and cost. 6

7 Table 1. Truth Table CONNECTION 0 A_ to _B1, LED_ to _LED1 1 A_ to _B2, LED_ to _LED2 Digital Control Inputs The provide a single digital control. controls the switches as well as the LED switches as shown in Table 1. Analog Signal Levels The on-resistance of the is very low and stable as the analog input signals are swept from ground to V+ (see the Typical Operating Characteristics). The switches are bidirectional, allowing A_ and _B_ to be configured as either inputs or outputs. ESD Protection The are characterized using the Human Body Model for ±15kV of ESD protection. Figure 5 shows the Human Body Model. This model consists of a 100pF capacitor charged to the ESD voltage of interest which is then discharged into the test device through a 1.5kΩ resistor. All signal and control pins are ESD protected to ±15kV HBM (Human Body Model). Applications Information Typical Operating Circuit The Typical Operating Circuit shows the MAX4890E/ MAX4892E in a 1000 Base-T docking station application. Power-Supply Sequencing and Overvoltage Protection Caution: Do not exceed the absolute maximum ratings. Stresses beyond the listed ratings may cause permanent damage to the device. Proper power-supply sequencing is recommended for all CMOS devices. Always apply V+ before applying analog signals, especially if the analog signal is not current limited. Layout High-speed switches require proper layout and design procedures for optimum performance. Keep design-controlled-impedance pc board traces as short as possible. Ensure that bypass capacitors are as close as possible to the device. Use large ground planes where possible. PROCESS: BiCMOS Chip Information 7

8 t ON t OFF 50% 50% _B1 50% 50% t OFF t ON 50% 50% 0V V IH V IL 0V _B2 A_ t PLH _B_ PULSE SKEW = t SK(p) = t PHL - t PLH THE SWITCHES ARE FULLY BIDIRECTIONAL. t PHL 3.0V 2.0V 1.0V V H 2.0V V L Figure 2. Turn-On and Turn-Off Times Figure 3. Propagation Delay Times 3.0V 2.0V A_ t PLHX t PHLX 1.0V R C 1MΩ R D 1500Ω V OH CHARGE-CURRENT LIMIT RESISTOR DISCHARGE RESISTANCE _B_ 2.0V V OL HIGH- VOLTAGE DC SOURCE Cs 100pF STORAGE CAPACITOR DEVICE UNDER TEST t PLHY t PHLY V OH 2.0V _B_ V OL OUTPUT SKEW = t SK(O) = t PLHY - t PLHX OR t PHLY - t PHLX THE SWITCHES ARE FULLY BIDIRECTIONAL. Figure 4. Output Skew Figure 5. Human Body ESD Test Model (MIL-STD-883, Method 3015) 8

9 DOCKING STATION NOTEBOOK CONNECTOR Typical Operating Circuit TRANSFORMER RJ-45 LED 0B2 1B2 2B2 3B2 TRD0_P TRD0_N A0 A1 4B2 5B2 6B2 7B2 ETHERNET PHY/MAC TRD1_P TRD1_N TRD2_P TRD2_N A2 A3 A4 A5 MAX4892E _LED2 0B1 1B1 TRD3_P TRD3_N A6 A7 2B1 3B1 4B1 5B1 TRANSFORMER RJ-45 LED_OUT LED_ 6B1 7B1 _LED1 _DOCK LED 9

10 A0 A1 A2 A3 A4 A5 A6 0B1 1B1 0B2 1B2 2B1 3B1 2B2 3B2 4B1 5B1 4B2 5B2 6B1 A0 A1 A2 A3 A4 A5 A6 Functional Diagrams 0B1 1B1 0B2 1B2 2B1 3B1 2B2 3B2 4B1 5B1 4B2 5B2 6B1 A7 7B1 A7 7B1 6B2 6B2 MAX4890E 7B2 LED0 LED1 7B2 0LED1 0LED2 1LED1 1LED2 LED2 2LED1 2LED2 MAX4892E 10

11 TOP VIEW Pin Configurations (continued) + A2 1 A3 2 N.C. 3 N.C. 4 N.C. 5 N.C. 6 A4 7 A1 A0 V+ 0B1 1B1 0B2 1B MAX4890E *EP 24 2B1 23 3B1 22 2B2 21 3B2 20 4B1 19 5B1 18 4B2 A B A6 A7 GND N.C. 7B2 6B2 7B1 6B1 TQFN *EXPOSED PADDLE CONNECTED TO GND. 11

12 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to QFN THIN.EPS 12

13 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to QFN THIN.EPS Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.